momentum and penetration

[foudarme]

a friend of mine, african PH, is making researches about the best african arrow buff criteria...

of course, he is completly convinced by all the ashby's conclusions and results: EFOC; COI tanto 3/1 grizz BH; ferule diameter's larger than shaft's diameter; arrow flechting and single bevel compatability; arrow heavy weight, etc.He has himself made penetration's tests in caffer buffs which claim some huge penetration differences' between the niddle and the tanto grizzly tip design when all the other ashby's factors are respected...

So there is the question: without any consideration about the poor trajectory quality which could result; without any consideration about the bow efficiency variations wich could result; can we consider that increasing undefinetly the weight of an ashby arrow would undefinitely increase the arrow's penetration when this arrow is shot with the same bow, at the same draw length and weight?...in other words, do a  1300 gr arrow perfectly tuned will penetrate more than the same 900gr arrow, perfectly tuned, when it is shot with the same bow...for instance with my 65#@29 ACS I get 0.78sfs with a 1330gr arrow and 0.61sfs for a 960gr arrow: can I be sure that the 1330gr will penetrate deeper than the 960 arrow or is there a downside to increase so much the arrow weight?

sorry for my poor american writing...

[O.L. Adcock]

MO continues to go up. The limiting factor is trajectory. One of the most basic functions of physics with a fixed amount of horsepower available, the slower you use it the more work it can do..By a factor of 4....Could be why we have low gears in our trucks!    ....O.L.

[foudarme]

         

just one of my friend's tests..1050gr arrow..30% FOC...59#@28 recurve bow...both rib shots
tanto tip / normal tip

[Bjorn]

Holy cow! Unless the upper shaft is 2 feet longer it would barely take out one lung!

[foudarme]

     

poor arrow penetration

[foudarme]

Originally posted by Bjorn:
Holy cow! Unless the upper shaft is 2 feet longer it would barely take out one lung!

it's just a test, the buff has been gun killed...

[foudarme]

tanto tip...excellent arrow penetration

         

[George D. Stout]

Those arrows also hit different areas with the one hitting lower penetrating further.  You don't know what other variables could have caused the difference: thicker ribs/cartilage, Skin thickness, etc.  You have to clear up any variables that could have entered the equation.

[robertson]

Hello

I am the guy whom has made this tests

i can say that both arrows , have taken the

middle of a rib .

One with a " tanto " head and the other ,with a

" needdle " head . Both broadheads are Grizzly

modified .

The arrows where exactly the same .

I made another test on another buff with the two

same arrows , and again the " tanto " had a

better penetration . But not so much difference

than the picture above .

[kibok&ko]

coucou les gars !!!

it's looks like the results of this test by O.L Addock give us almost a definitive answer ...

The KE curve is almost flat from 450 grs to 700 grs ...

The momentum is always going up ...

Non ?

[O.L. Adcock]

Here is the rest of the chart on that bow. Velocity vs momentum. Keep in mind these reading were off a shooting machine so they are a bit higher then they would be with fingers but the relationships would be the same...O.L.

 

[MikeW]

I have a stupid question, if the tanto tip penetrates so much better why are they harder to push into the foam of my broadhead quiver?

I have 3 of the Ashley heads and they require quite a bit more force to get started in the foam than my STOS or WW's do. I can understand they may go through bone easier but in my mind that doesn't mean they penetrate better overall. Only means they penetrate better if they hit bone.
???

[Traditional-Archer]

O.L,
Hello,
Do you see a chart in the future that will show let say for example.

Arrow is a gold tip 28.25" long with the balance point being 7.25 (tip weight 300-g)giving us a FOC of 24.33.

I guess what I am asking is, there are probably to many variables to have a chart that would show all arrows and arrow lenghths and tip weight.or am I off base.

That being, that all bows are not created equally. All arrows are not created equally,
I was thinking a chart for a given bow weight and the best arrow tip combination combined.
Just a thought.